A truss is a structural framework of wood or metal arranged in a pattern which is used to support roofs or bridges. The structure of a truss made of iron rods is shown in the figure below.

The rods $EF, DG, AH, IK$ and $JL$ are perpendicular to the base $BC$. A number of triangles are formed by the rods.

In the triangle $ABC$, side $AB = AC$. In the triangle $AGK$, all sides are equal and $H$ is the mid-point of $GK$.

The sides of triangle $IJL$ are of length $3 m, 4 m$ and $5 m$. Is triangle $IJL$ an isosceles triangle? Why?

The figure given below shows a tyre of a bicycle.

What type of angle does Spoke $1$ make with Spoke $11$?

The figure below shows a combination of shapes.

In the figure, $US$ is parallel to $WP$ and $UV$ is parallel to $QP$.

$PQRS$ is a square. $WRTU$ is a rectangle. $PSW$ and $WUV$ are triangles.

Arun joins $S$ and$Q$ . $SQ$ is an extension of $US$. Which type of quadrilateral is $PQUV$? Justify your answer.

The figure below shows a combination of shapes.

In the figure, $US$ is parallel to $WP$ and $UV$ is parallel to $QP$.

$PQRS$ is a square. $WRTU$ is a rectangle. $PSW$ and $WUV$ are triangles.

Which of the following quadrilaterals is regular?

The figure below shows a combination of shapes.

In the figure, $US$ is parallel to $WP$ and $UV$ is parallel to $QP$.

$PQRS$ is a square. $WRTU$ is a rectangle. $PSW$ and $WUV$ are triangles.

Looking at the figure, Raji claims that, ‘$PWUS$ is a rhombus’. Do we have sufficient information to accept her claim? Justify your answer.

Usha took a photo of a spider web in her farm. 

To which of the following polygons does the shape in the photo resemble?

Ammu drew different shapes in her drawing book. 

Of the figures she drew, how many were polygons?

How many trapeziums are there in the following figure?